perform a redirect in output filter

[John Zhang <jo...@yahoo.com>]

I am using apache 2.0/2.2, in my output filter, I
would like to have the ability to redirect.  Some
tests indicated that I can redirect to a page on the
same site, but not to an external site.

Here is my code for redirect:
char* location = 
    apr_table_get(r->headers_out, "Location");
//Note this Location is set by my filter during the
process, so I know I need to do a redirect.
if(location && location[0])
{
  //r->status = 301;
  r->method = apr_pstrdup(r->pool, "GET");
  r->method_number = M_GET;
  apr_table_unset(r->headers_in, "Content-Length");
  ap_remove_output_filter(my_filter);
  ap_internal_redirect_handler(location, r);
  return APR_SUCCESS;
}

//tests: (if my site is http://localhost/foo)
and when http://localhost/foo/bar.html (my test
page)is loaded I want to redirect it to
a) /foo/foo2/existing.html (works)
b) http://localhost/foo/foo2/existing.html (works)
c) http://www.google.com (does not work), instead I
get http://localhost/foo displayed on the browser.

Is there anything I did is incorrect?  I noticed the
method is called "*internal_redirect*", but did not
know another one for "external redirect".

Thanks,
John

Re: perform a redirect in output filter

[John Zhang <jo...@yahoo.com>]

--- On Thu, 4/17/08, Joe Lewis <jo...@joe-lewis.com> wrote:

> From: Joe Lewis <jo...@joe-lewis.com>
> Subject: Re: perform a redirect in output filter
> To: modules-dev@httpd.apache.org
> Date: Thursday, April 17, 2008, 6:05 AM
> John Zhang wrote:
> > I am using apache 2.0/2.2, in my output filter, I
> > would like to have the ability to redirect.  Some
> > tests indicated that I can redirect to a page on the
> > same site, but not to an external site.
> >
> > Here is my code for redirect:
> > char* location = 
> >     apr_table_get(r->headers_out,
> "Location");
> > //Note this Location is set by my filter during the
> > process, so I know I need to do a redirect.
> > if(location && location[0])
> > {
> >   //r->status = 301;
> >   r->method = apr_pstrdup(r->pool,
> "GET");
> >   r->method_number = M_GET;
> >   apr_table_unset(r->headers_in,
> "Content-Length");
> >   ap_remove_output_filter(my_filter);
> >   ap_internal_redirect_handler(location, r);
> >   return APR_SUCCESS;
> > }
> >
> > //tests: (if my site is http://localhost/foo)
> > and when http://localhost/foo/bar.html (my test
> > page)is loaded I want to redirect it to
> > a) /foo/foo2/existing.html (works)
> > b) http://localhost/foo/foo2/existing.html (works)
> > c) http://www.google.com (does not work), instead I
> > get http://localhost/foo displayed on the browser.
> >
> > Is there anything I did is incorrect?  I noticed the
> > method is called "*internal_redirect*", but
> did not
> > know another one for "external redirect".
> >   
> 
> An internal redirect should only work with internal
> redirects, and I do 
> not know of an external.
> 
> I expect that you will have to set the f->r->status
> to 302, and maybe 
> return a small page saying that the doc moved.  Have you
> uncommented the 
> r->status line and commented out the internal_redirect
> line?  How did 
> that work?  (Note: an output filter, probably shouldn't
> be calling a 
> handler.  You may want to destroy the bucket brigade, and
> then create a 
> new bucket brigade with the error message.)
> 
Thanks Joe,
It worked if I do not use the internal redirect API.

Re: perform a redirect in output filter

[Joe Lewis <jo...@joe-lewis.com>]

John Zhang wrote:
> I am using apache 2.0/2.2, in my output filter, I
> would like to have the ability to redirect.  Some
> tests indicated that I can redirect to a page on the
> same site, but not to an external site.
>
> Here is my code for redirect:
> char* location = 
>     apr_table_get(r->headers_out, "Location");
> //Note this Location is set by my filter during the
> process, so I know I need to do a redirect.
> if(location && location[0])
> {
>   //r->status = 301;
>   r->method = apr_pstrdup(r->pool, "GET");
>   r->method_number = M_GET;
>   apr_table_unset(r->headers_in, "Content-Length");
>   ap_remove_output_filter(my_filter);
>   ap_internal_redirect_handler(location, r);
>   return APR_SUCCESS;
> }
>
> //tests: (if my site is http://localhost/foo)
> and when http://localhost/foo/bar.html (my test
> page)is loaded I want to redirect it to
> a) /foo/foo2/existing.html (works)
> b) http://localhost/foo/foo2/existing.html (works)
> c) http://www.google.com (does not work), instead I
> get http://localhost/foo displayed on the browser.
>
> Is there anything I did is incorrect?  I noticed the
> method is called "*internal_redirect*", but did not
> know another one for "external redirect".
>   

An internal redirect should only work with internal redirects, and I do 
not know of an external.

I expect that you will have to set the f->r->status to 302, and maybe 
return a small page saying that the doc moved.  Have you uncommented the 
r->status line and commented out the internal_redirect line?  How did 
that work?  (Note: an output filter, probably shouldn't be calling a 
handler.  You may want to destroy the bucket brigade, and then create a 
new bucket brigade with the error message.)

Joe
-- 
Joseph Lewis <http://sharktooth.org/>